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most shops have parts washers with washer solvent that gets delivered and picked up by companies like safety kleen.
other shops use brake clean in rattle cans those are available at all parts stores.
the brake rotors and drums are cleaned once their taken out of the box.
the pads and shoes are never cleaned when new. but the shoes are usually cleaned and adjusted while on the car. once every 6000 miles
PADS are never cleaned at all, the rest of them just like I mentioned in the first reply either with aparts washer or brake clean in a spray can.
this was my answer early